1. Field of the Invention
The present invention relates generally to data communications systems and, more particularly to, a method of transferring a data signal in a contiguous sequence over a channel.
2. Prior Art
Typically, a data signal is transmitted over a channel in a fixed length data packet. The source of the data signal, typically a sensor, is generally allocated to a fixed slot or port, and communication systems are limited by the number and types of sensors that can be used. The addition of a sensor generally requires reconfiguring the hardware of the system.
The size of a channel, or the amount of information that can be transmitted over the channel in one packet is also limited. Typically, the data signal is broken down into a variable number of fixed size data packets, each having its own header and identifier. The data packets are transmitted over the link and must be reorganized and reassembled into the original message on the receiving side. For example, U.S. Pat. No. 5,870,394 to Oprea discloses a method and apparatus for the reassembly of data packets into messages. In Oprea, messages are defined into a plurality of data packets having respective header and payload portions. The header portion includes information related to the channel associated with the data packet and whether or not the data packet is the final data packet in the message. The reassembly processor must reassemble the different data packets from different channels into a contiguous message format.
The present invention is directed to, in a first aspect, a method of formatting a data packet frame for transmitting a data signal in a contiguous sequence over a channel. The method comprises determining the length of the data signal and appending a header to the data signal. Preferably, the header includes information corresponding to the length of the data signal. In the preferred embodiment, the information corresponding to the length of the data signal is used by the recipient to receive the data signal in the contiguous sequence.
In another aspect, the present invention is directed to a method of sending data from a source to a recipient over a channel in a contiguous sequence. The method comprises appending a header to the data signal, the header including a length information corresponding to a length of the data signal, and transmitting the header and data signal over the channel. In the preferred embodiment, the data signal is transmitted in a contiguous sequence. The method further comprises receiving the header and data signal, and using the length information corresponding to the length of the data signal to receive the data signal aligned in the same contiguous sequence as it was transmitted.